Debug Build

An app could be developed as a debug build. This should not be the release build.

AndroidManifest.xml

Check for android:debuggable within the AndroidManifest.xml

Drozer

run app.package.attacksurface com.you.app

or

run app.package.debuggable

run-as

If an app is debuggable you can execute commands as the user of the application.

adb shell
run-as com.your.app
id (or other command to run)